1. Field of the Invention
The present invention relates to an infrared remote control device used for a plasma display device.
2. Description of the Related Background Art
Most remote control devices used to remotely control video equipment employ infrared rays as carriers of a remote control signal transmitted from a transmitter thereof. Since the directional angle of the infrared rays is easily controlled, the video equipment can be usually controlled without exerting an influence upon equipment other than the video equipment if the infrared emission direction of the remote control device is aimed roughly at the video equipment.
When a plasma display device is used as a video equipment, discharge is continuously carried out between electrodes of a discharge cell (for performing discharge) that constitutes each pixel of the plasma display panel during an emission sustaining period for maintaining the light emission of the discharge cell. It is known that a large amount of infrared noise of an infrared frequency band is produced because of the heat of the cell that is discharging. Since the infrared noise is emitted from the display screen of the plasma display device, an infrared-ray receiving portion for remote control in the plasma display device is situated at a position slightly further inside than the display screen in the surface of the plasma display device so that the infrared noise does not reach the receiving portion thereof. Therefore, an infrared-receptive angle range of the infrared-ray receiving portion of the plasma display device is narrowed, and, disadvantageously, the plasma display device cannot be remotely controlled unless a user operates the transmitter of the remote control device to point the infrared emission direction thereof toward the infrared-ray receiving portion of the plasma display device with accuracy.
It is therefore an object of the present invention to provide a remote control device that is capable of remotely controlling a plasma display device with good operability and with accuracy by excluding influence of infrared noise.
The infrared remote control device according to the present invention is used for a plasma display device in which each field is divided into an address period for setting a discharge cell that constitutes each pixel to either a light emission cell or a non-light emission cell in accordance with pixel data and an emission sustaining period for causing only the discharge cell set as the light emission cell to emit light, in order to drive the plasma display panel, the infrared remote control device comprising: a light-reception portion for obtaining a light-reception signal by reception of infrared rays and for demodulating the light-reception signal; a removing device for removing a signal component during the emission sustaining period from an output signal of the light-reception portion and for outputting a remaining signal component after removing; a delaying device for delaying the output signal of the removing device in a field unit; a logical-sum device for calculating a logical sum of the output signal of the removing device and an output signal of the delaying device; and a determining device for determining a content of a remote control signal that controls an operation of the plasma display device in accordance with the logical sum calculated by the logical-sum device.